剑指offer-24-反转链表-golang

题目：定义一个函数，输入一个链表的头节点，反转该链表并输出反转后链表的头节点。

type Node struct {
	val  int
	next *Node
}

func reverseList(head *Node) *Node {
	if head == nil || head.next == nil {
		return head
	}
	front, middle, tail := head.next.next, head.next, head
	tail.next = nil
	for front != nil {
		middle.next = tail
		tail = middle
		middle = front
		front = front.next
	}
	middle.next = tail
	return middle

}